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%I #9 Jun 26 2018 06:09:29
%S 6,36,72,144,360,900,2160,5184,12528,30276,73080,176400,425880,
%T 1028196,2482272,5992704,14467680,34928100,84323880,203575824,
%U 491475528,1186526916,2864529360,6915585600,16695700560,40306986756,97309674072
%N Number of 3 X n 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 0 and 1 1 1 vertically.
%C Row 3 of A207928.
%H R. H. Hardin, <a href="/A207929/b207929.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2*a(n-1) + 2*a(n-3) + a(n-4) for n>5.
%F Empirical g.f.: 6*x*(1 + 4*x - 2*x^3 - x^4) / ((1 + x^2)*(1 - 2*x - x^2)). - _Colin Barker_, Jun 26 2018
%e Some solutions for n=10:
%e ..1..1..0..1..1..1..0..1..1..0....1..0..1..1..0..1..1..1..1..1
%e ..0..0..1..1..0..0..1..1..0..0....1..0..0..1..1..0..1..1..0..0
%e ..0..1..1..0..1..1..1..0..0..1....0..1..1..0..1..1..0..0..1..1
%Y Cf. A207928.
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 21 2012
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